The present invention relates to an apparatus and a method for producing an article made of thermoplastic and thermosetting materials.
The invention was developed in particular for the production of articles formed by compression moulding of one or more plates, or sandwich, between two heated half-moulds provided with respective compression moulding surfaces. For the production of articles made of thermosetting material, plates or sheets constituted by fibres incorporated in a thermosetting resin, initially in the viscous or plastic state, are used. The material in sheet or plate form is compressed between the compression moulding surfaces of two half-moulds, movable with respect to one another between an open position and a closed position. During compression in the mould, the thermosetting material is heated in contact with the two half-moulds, until obtaining the polymerisation and hardening of the thermosetting resin.
In many technical sectors, in particular in the automotive industry, there is a need to provide reinforcing areas or fastening materials made of thermoplastic material on one or more faces of an article made of thermosetting material obtained by compression moulding. Current technology for the production of articles for the automotive industry obtained by compression moulding a thermosetting material, requires separately to produce by injection moulding reinforcing organs or fastening organs which, in a step following the thermo-compression moulding of the thermosetting material, are fastened onto one or more faces of the article made of thermosetting material by gluing, welding or by mechanical fastening means.
In the sector of moulding of articles made of compression moulded thermoplastic material, a method has already been proposed for forming by means of injection moulding a component anchored onto a surface of a plate made of thermoplastic material whilst said plate is compression moulded between two mutually facing surfaces of two half-moulds. For instance, the document EP-A-1153735 by the same Applicant discloses a method and an apparatus which provide an injection moulding cavity obtained in one of the two half-shells and which terminates on the compression moulding surface of the same half-shell by means of a restricted section to prevent the injection moulded material from damaging the compression moulded plate.
However, this technology cannot be immediately transferred to the sector of thermo-compression moulding of articles made of thermosetting materials, especially if an injection moulded component is to be formed on an extended surface portion of an article made of thermosetting material, due to the different behaviour of thermosetting materials with respect to thermoplastic materials during compression moulding.